Destinations

A destination is a system instances are sent to: a PACS, an archive or VNA, an AI service, a workstation. Configuration › Destinations. There are three kinds:

• DICOM: a storage endpoint reached with C-STORE (this page).
• DICOMweb: a cloud PACS or service reached with STOW-RS.
• Group: several destinations that fail over or share the load.

Connection

Setting	Default	Notes
Host, port		The destination’s address and DICOM port.
Called AE title		The destination’s AE title.
Calling AE title	the router’s AE title	What the router calls itself to this destination, when it expects something else.
Associations per node	2	Parallel associations from each node.
Asynchronous window	1	C-STORE requests outstanding per association; more speeds up distant destinations that support it.
DICOM TLS	off	Encrypted connections; see DICOM TLS.

Make sure the destination accepts the router: add the router’s AE title and every node’s address to its list of allowed senders. Echo on the destinations list checks the connection, from the central server.

Queues and retries

Each node keeps a queue on disk for each destination. Destinations do not wait for each other: a PACS that is down does not hold up the archive.

• Retries: an instance the destination refuses with a status worth retrying is tried again after the retry delay (default 5 s), doubling up to the maximum retry delay (300 s), up to max attempts (10).
• Unreachable: a destination that cannot be reached at all is unreachable. Its queue waits without using attempts, and an alert is raised after the time set on the Alerts tab.
• Idle checks: a destination nothing has been sent to for a while is checked by each node every 5 minutes (Settings › Check idle destinations; 0 turns this off): a C-ECHO, or for DICOMweb a search with its credentials. One that does not answer is marked unreachable, with the reason (Idle check: …), so the alert and failover groups act before any study is sent to it. Destinations that are receiving studies are not checked: the traffic shows they work.
• Dead letters: an instance refused for good, or that used all its attempts, becomes a dead letter, kept on the node with the reason. History › Dead letters lists them across nodes, to re-queue after fixing the cause, send elsewhere, purge or download.

Delivery is at least once: if a crash loses an acknowledgment, the instance is sent again, which a PACS takes as a resend of the same instance.

What is sent

• Transfer syntaxes: the encodings the destination receives, most preferred first; instances are converted when needed.
• Tag edits and a script, applied as each instance is sent. The router’s own copy never changes.
• De-identification: a profile that removes identities before anything leaves.

When it is sent

• Bandwidth and schedules: limits and pause windows by time of day.
• Priority: instances of high-priority routes go first; see Routes.

More

• Storage commitment: ask the destination to confirm it holds what it was sent.
• Archive: let the router search and retrieve from it, for viewers and prior studies.
• Test syntaxes proposes the destination’s transfer syntax list for one kind of each image, and shows what it accepts.